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Nucleation and Grain Boundaries in Thin Film CdTe/CdS Solar Cells

Published online by Cambridge University Press:  31 January 2011

Jon D Major
Affiliation:
j.d.major@durham.ac.uk, Durham University, Department of Physics, Durham, United Kingdom
Yuri Y Proskuryakov
Affiliation:
y.y.proskuryakov@durham.ac.uk, Durham University, Department of Physics, Durham, United Kingdom
Ken Durose
Affiliation:
ken.durose@durham.ac.uk, Durham University, Department of Physics, South Road, Durham, DH1 3BH, United Kingdom
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Abstract

The early stage formation mechanisms operating during the sublimation growth of CdTe films on CdS has been evaluated using a growth interrupt methodology for deposition under 100 Torr of N2. Key stages of the growth were identified and are discussed in terms of the processes of island nucleation, island growth/coalescence, channel formation and secondary nucleation that have been reported for other materials systems. It was demonstrated that the grain size could be manipulated by means of controlling the gas pressure in the range 2 – 200 Torr, with the grain diameter increasing with pressure linearly as D (μm) = 0.027(± 0.011) × P (Torr) + 0.90(± 0.31). For a series of solar cells made using such material, the performance parameters were seen to increase with grain size up to a plateau corresponding to grains of ∼4 μm in this case. Equivalent circuit parameters for resistive components arising from grain boundaries, and the contact to the CdTe, were measured. It is considered that grain boundary barriers in CdTe are harmful to PV performance, and that the plateau in performance occurs when the grain size is increased to the level where the contact resistance is greater than that due to grain boundaries.

Type
Research Article
Copyright
Copyright © Materials Research Society 2009

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References

1. Willoughby, A. F. W. in Narrow-Gap II-VI Compounds for Optoelectronic and Electromagnetic Applications, edited by Capper, P. (Chapman and Hall, London, 1997), Vol. 3, pp. 268290.Google Scholar
2. Durose, K. Sadler, J.R. E. Yates, A. J. W. and Szczerbakow, A. in 28th IEEE Photovoltaic Specialists Conf., edited by Rohatgi, A. (IEEE, Anchorage, Alaska, USA, 2000), pp. 487.Google Scholar
3. Pike, G. E. and Seager, C. H. J. Appl. Phys. 50 (5), 34143422 (1979).Google Scholar
4. Woods, L. M. Robinson, G. Y. and Levi, D. H. in 28th IEEE Photovoltaic Specialists Conference (IEEE, Anchorage, Alaska, USA, 2000), pp. 603606.Google Scholar
5. Galloway, S. A. Edwards, P. R. and Durose, K. Solar Energy Materials and Solar Cells 57, 6174 (1999).Google Scholar
6. Visoly-Fisher, I., Cohen, S. R. Ruzin, A. and Cahen, D. Advanced Materials 16 (11), 879883 (2004).Google Scholar
7. Thorpe, T. P. Fahrenbruch, A. L. and Bube, R. H. J. Appl. Phys. 60 (10), 3622 (1986).Google Scholar
8. Sites, J. R. Granata, J. E. and Hiltner, J. F. Solar Energy Materials and Solar Cells 55, 4350 (1998).Google Scholar
9. Cousins, M. A. and Durose, K. Thin Solid Films 361-362, 253257 (2000).Google Scholar
10. Moutinho, H. R. Al-Jassim, M. M., Levi, D. H. Dippo, P. C. and Kazmerski, L. L. J. Vac. Sci. Technol. A 16 (3), 1251 (1998).Google Scholar
11. Moutinho, H. R. Dhere, R. G. Al-Jassim, M. M., Levi, D. H. and Kazmerski, L. L. J. Vac. Sci. Technol. A 17 (4), 1793 (1999).Google Scholar
12. Cousins, M. A. and Durose, K. in 16th PVSEC (Glasgow, 2000), Vol. Vol I, pp. 834.Google Scholar
13. Eckertova, L. Physics of Thin Films. (Plenum Publishing Corporation, New York, 1986).Google Scholar
14. Neugebauer, C. A. Handbook of Thin Film Technology. (McGraw-Hill Book Company, New York, 1970).Google Scholar
15. Barna, P. B. and Reicha, F. M. in 8th International Vacuum Congress (Cannes, 1980), pp. 165168.Google Scholar
16. Barna, P. B. Reicha, F. M. Barcza, G. Gosztola, L. and Koltai, F. Vacuum 33, 2530 (1983).Google Scholar
17. Pocza, J. F. Barna, A. and Barna, P. B. J. Vac. Sci. Technol. 6, 472475 (1969).Google Scholar
18. Pocza, J. F. Barna, A. Barna, P. B. Pozgai, I. and Radnoczi, G. Japanese Journal of Applied Physics Supplement 2, 525532 (1974).Google Scholar
19. Anton, R. Phys. Rev. B (Condensed Matter and Materials Physics) 70 (24), Art No 245405 (2004).Google Scholar
20. Pashley, D. W. Stowell, M. J. Jacobs, M. H. and Law, T. J. Philosophical Magazine 10, 127158 (1964).Google Scholar
21. Proskuryakov, Y. Y. Durose, K. Taele, B. M. and Oelting, S. J. Appl. Phys. 102 (2), Art No 024504 (2007).Google Scholar